Robert Brown
A botanist who discovered the nucleus in plant cells and described Brownian motion, the random movement of particles in a fluid.
Most quoted
"I have, however, been enabled to satisfy myself that the particles or molecules of the pollen of plants, and indeed of many other organic as well as inorganic bodies, when suspended in water, are in a state of constant and rapid oscillatory motion."
— from A Brief Account of Microscopical Observations Made in the Months of June, July, and August, 1827, on the Particles Contained in the Pollen of Plants; and on the General Existence of Active Molecules in Organic and Inorganic Bodies., 1827
"This motion was such as to satisfy me, after frequently repeated observation, that it was not caused either by currents in the fluid, or by its gradual evaporation, but belonged to the particle itself."
— from A Brief Account of Microscopical Observations Made in the Months of June, July, and August, 1827, on the Particles Contained in the Pollen of Plants; and on the General Existence of Active Molecules in Organic and Inorganic Bodies., 1827
"This motion was such as to satisfy me, after frequently repeated observation, that it arose neither from currents in the fluid, nor from its gradual evaporation, but belonged to the particle itself."
— from A Brief Account of Microscopical Observations Made in the Months of June, July, and August, 1827, on the Particles Contained in the Pollen of Plants; and on the General Existence of Active Molecules in Organic and Inorganic Bodies, 1827
All quotes by Robert Brown (343)
The motion is not due to any chemical action or decomposition.
The motion is not affected by changes in temperature, as long as the fluid remains liquid.
The motion is not diminished by the addition of substances that would destroy vitality.
The motion is exhibited by particles of all sizes, as long as they are sufficiently minute.
The motion is more vigorous in smaller particles.
The motion is a general property of matter in a finely divided state.
The motion is a phenomenon of great theoretical interest.
The motion may afford a clue to the ultimate constitution of matter.
The motion is not explicable by any known laws of hydrodynamics.
The motion is a distinct and peculiar phenomenon, requiring further investigation.
The motion is not a mere optical illusion.
The motion is a real and constant movement of the particles.
The motion is a universal property of minute particles in a fluid medium.
The cell is the fundamental unit of life, a microcosm of organization and function.
In observing the minute motions of particles within pollen grains, I saw a world of ceaseless, random activity—a signature of life at its most basic.
Nature does not proceed by leaps, but by the patient accumulation of small variations.
The nucleus of the cell is not a mere vesicle; it is the central governing body, the archive of hereditary instruction.
To name a plant is but the first step; to understand its structure and relation to others is the true aim of botany.
In the chaos of Brownian motion, I found not disorder, but the fundamental physical principle underlying life's dynamism.
The flora of Australia presents a world apart, a testament to the long isolation and peculiar creativity of nature.
Contemporaries of Robert Brown
Other Biologys born within 50 years of Robert Brown (1773–1858).